Hope this finds its way onto the forum:
For those of you that grow nerine sarniensis here is an observation-
(and we knows what we are talking about!)
We frequently make a comparison between bulbs grown in clay pots and
bulbs grown in plastic pots and can now make a definitive statement:
The bulbs in clay pots shrink by to 30% of their pre-flowering size
whilst the bulbs grown in plastic pots continue to hold their full
pre-flowering size - you know how the bulb swells in August-September
(and if your bulbs don't swell in September then you are doing
something wrong (if you are in the Northern Hemisphere of course). We
also note that seedling bulbs can be kept in stasis in small plastic
seed trays for many years without adverse effect, other than the bulb
size stays small, and only when repotted (we have some bulbs in this
growing scenario that are 8 years old) do the bulbs then get up to a
decent size and the tiny bulbs, like bonsais, produce diminutive
flower heads- we had a collection of the Zinkowski nerines that were
tiny bulbs to start with and they had tiny flowers, and I thought
that they were poor, however given the Exbury Regime, they are now
reaching their full potential as they should be.
Of course, you might say, that other factors are involved... so I can
also say that the ones in clay and the others in the sample that I
measured against were potted up in the same year. We also split the
pots and examine the roots and notice substantial differences in root
growth patterns between clay and plastic. In clay the bulbs put a
out much greater mass of fibrous roots that cling to the clay
surface, whereas in plastic they are more evenly spread and not in
such abundance. We surmise, therefore, that the bulb is losing mass
to this root growth, which is deleterious to flowering. With our
potting mix of 5 parts John Innes No 3, 1 part course grit, 1 part
sand, 1 part bulb fibre, 1 part rotten manure, we are achieving 95%
flowering in all our 2 litre show pots. We feed with a 20-20-20
fertiliser in a weak dilution from now until March.
This year the Exbury Nerine Collection (see
<http://www.nerines.com/>http://www.nerines.com/ for varieties etc) has
flowered about 3 weeks earlier than usual- This we attribute to a
really dull August when the weather here in the southern UK was
miserable (please don't feel sorry for me I went to Zanzibar instead)
however it was noted that there was almost autumnal temperature
fluctuations with very cool nights. This, we believe, triggered the
flower spikes to start growing, and once this happens they do not
stop even if the temperatures then rise again..
Now we have just had a heat wave with record 30 degrees at the start
of Oct. and quite a few are wilting faster. We keep a 50% shade over
them for most of the year.
So my message to all you n. saniensis growers is- ditch your clay and
go plastic....
Nick de Rothschild